This troubleshooting procedure checks the following components if a problem is suspected.
- Wiring
- Switches
- Electronic Control Module (ECM)
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| Illustration 1 | g01060444 |
Test Step 1. Inspect Electrical Connectors and Wiring
- Turn the keyswitch OFF/RESET.
- Thoroughly inspect the J61/P61 customer connector, the J1/P1 ECM connector, and the J2/P2 ECM connector. Refer to Troubleshooting, "Electrical Connectors - Inspect" for details.
- Perform a 45 N (10 lb) pull test on each of the wires in the customer connector and the ECM connector that are associated with the diagnostic lamp. Refer to illustration 1.
- Check the J61/P61 customer connector (allen head screw) for the proper torque of 2.25 ± 0.25 N·m (20 ± 2 lb in).
Check the ECM connector J1/P1 and J2/P2 for the proper torque of 6.0 N·m (55 lb in).
- Check the harness and wiring for abrasions and for pinch points from the battery to the ECM.
Expected Result:
All connectors, pins, and sockets are completely coupled and/or inserted. The harness and wiring are free of corrosion, of abrasion, and of pinch points.
Results:
- OK - The wiring and connectors are okay. Proceed to Test Step 2.
- Not OK -
Repair: Repair the connectors or wiring and/or replace the connectors or wiring. Ensure that all of the seals are properly in place and ensure that the connectors are completely coupled.Verify that the repair eliminates the problem.
Stop.
Test Step 2. Verify the Negative Battery Connections
- Locate the negative battery bus bars and verify that the connections are installed properly.
Refer to Troubleshooting, "Engine Wiring Information" for additional information.
Expected Result:
The negative battery connections have been properly installed.
Results:
- OK - The connections for the negative battery bus bar have been installed properly. Proceed to Test Step 3.
- Not OK -
Repair: Make the necessary connections in order to ensure proper installation.
Stop.
Test Step 3. Check the Status of the Switch
- Connect the electronic service tool to the service tool connector.
- Turn the keyswitch to the ON position.
- Monitor the status screen on the electronic service tool while each switch is cycled.
Expected Result:
Each switch is displayed as "ON" and "OFF" when the switch is cycled.
Results:
- OK - The switches are operating properly. Stop.
- Not OK - There is a problem with the wiring or the switch. Proceed to Test Step 4.
Test Step 4. Bypass the Switch
- Make a jumper wire that is 100 mm (4 inch) long. Use two 9W-0852 Connector Pin on the ends of the wire.
- Turn the keyswitch to the OFF/RESET position.
- Install the jumper wire across the switch that is suspect.
- Turn the keyswitch to the ON position.
- Monitor the status screen on the electronic service tool for the suspect switch.
Expected Result:
The switch status changes for the suspect switch.
Results:
- OK - The switch status changed.
Repair: Replace the switch.Verify that the repair solved the problem.
Stop.
- Not OK - The switch status did not change. Proceed to Test Step 5.
Test Step 5. Check the Negative Battery Wiring for the Suspect Switch
- Turn the keyswitch to the OFF/RESET position.
- Measure the resistance between the negative battery terminal on the suspect switch and a negative battery connection that is in close proximity. Check in order to ensure that the negative battery connection is good.
Expected Result:
The resistance is less than 10 Ohms.
Results:
- OK - The resistance is less than 10 Ohms. The wiring between the switch and the negative battery is okay. Proceed to Test Step 6.
- Not OK - The resistance is greater than 10 Ohms.
Repair: Replace the wire.Verify that the repair eliminates the problem.
Stop.
Test Step 6. Check for an Open between the Switch and the ECM
- Turn the keyswitch OFF/RESET.
- Disconnect the ECM connector P1 from the ECM.
- Measure the resistance between the suspect switch input on the ECM connector P1 and the suspect switch.
Wiggle the harness during the measurement. This will help reveal an intermittent condition.
Expected Result:
The resistance is less than 10 Ohms.
Results:
- OK - The resistance is less than 10 Ohms. Proceed to Test Step 7.
- Not OK - The resistance is more than 10 Ohms. The resistance of the wire indicates an open or excessive resistance.
Repair: Repair the wiring or replace the wiring.Verify that the repair eliminates the problem.
Stop.
Test Step 7. Check for a Short Circuit between the Switch and the ECM
- Disconnect the ECM connector P1 from the ECM.
- Measure the resistance between the input for the suspect switch on the ECM connector P1 and every wire in the P1 connector. Measure the resistance between the input for the suspect switch on the ECM connector P1 and engine ground.
Expected Result:
The resistance is more than 20,000 Ohms.
Results:
- OK - The resistance is more than 20,000 Ohms. Proceed to Test Step 8.
- Not OK - The resistance is less than 20,000 Ohms.
Repair: Repair the wiring or replace the wiring.Verify that the repair eliminates the problem.
Stop.
Test Step 8. Check the voltage at the ECM
- Turn the keyswitch to the OFF/RESET position.
- Remove the suspect switch wire from the P1 ECM connector. Install a wire jumper into the socket for the suspect switch wire.
- Turn the keyswitch to the ON position.
- Alternately ground the wire jumper.
- Monitor the status screen on the electronic service tool for the suspect switch.
Expected Result:
The switch status changes for the suspect switch.
Results:
- OK - The switch status changes for the suspect switch.
Repair: The problem may be intermittent. If the problem is intermittent, refer to the diagnostic functional test Troubleshooting, "Electrical Connectors - Inspect".
Stop.
- Not OK - The switch status does not change for the suspect switch.
Repair: Perform the following procedure.
- Temporarily connect a spare ECM.
- Cycle the suspect switch and monitor the switch status on the electronic service tool.
- If the problem is resolved with the spare ECM, then reconnect the suspect ECM.
- If the problem returns with the suspect ECM, then replace the ECM.
Stop.